Sand core structure for air flue of cylinder cover of engine

Abstract

The invention discloses a sand core structure for an air flue of a cylinder cover of an engine. A sand core comprises a core body and core heads at two ends of the core body; the core head at one end of the core body is fixed after being inserted into a core head base on a water channel core; the core head at the other end is fixed on a metal mould; the core head which is fixed in the core head base on the water channel core of the core body has a cylindrical structure; the core head is axially and vertically inserted into the core head base of the water channel core; and the core head of the core body fixed on the metal mould has a structure with a cross section of stair shape. By adopting the technical scheme, compared with the prior art, the sand core structure has the advantages that the cylindrical core head of the sand core of the air flue is fixed after being vertically inserted into the core head base on the water channel core; due to the cylindrical structure, the core-disassembling operation is easily performed; the positioning precision is high; no edged structure exists; the bumping and sand dropping are difficult to occur; when the stair-shaped core head at the other end of the sand core of the air flue is fixed, no side mould is required for positioning; the displacement of the sand core of the air flue caused by matching problem of the mould during the mould-combining process is avoided; and the positioning precision is higher.

Description

technical field [0001] The invention relates to casting equipment for an engine cylinder head, in particular to a sand core structure for an engine cylinder head airway. Background technique [0002] The intake and exhaust passage structures are an important part of the aluminum alloy cylinder head structure. One end is connected to the end face of the combustion chamber, and the other end protrudes from the side opening. Its dimensional accuracy and internal surface quality have an important impact on the overall performance of the cylinder head. . Because the airway structure is located inside the cylinder head, and its shape is mostly curved, its quality mostly depends on the casting process of this part. In the casting process of aluminum alloy cylinder heads, people often use resin airway sand cores with high strength and smooth surface to form the cylinder head airway structure. [0003] At present, in the airway sand core structure used in domestic aluminum alloy cy...

AI Technical Summary

Problems solved by technology

However, this airway sand core structure has the following disadvantages: (1) the positioning accuracy of the square core head of the airway core is relatively poor; There is still a gap of 0.2-0.5mm between the matching core seats, which causes the airway core to float up under the action of the aluminum liquid during the pouring process.

What's more serious is that the height of the boss of the valve guide hole of the cylinder head has a large deviation, usually 0.5-1mm, and the height of the boss of the valve guide hole of the cylinder head directly affects the performance parameter of the intake air—the turbine ratio; (2) The square core head structure of the airway core has edges and corners. First, it is not easy to operate the core. Secondly, during the core setting process of this structure, it is easy to bump and rub and cause sand loss, which affects the quality of the casting after casting.

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